Electronic circuit components, such as resistors and active filters can be replaced by switched capacitor circuitry. Switched capacitor circuits allow tunable analog circuits to be manufactured with minimal use of resistors. Resistors may be difficult to integrate on silicon substrates, and can make the integrated circuit bulky. The switched capacitor circuits are typically used in order to integrate both analog and digital circuits on a single silicon chip. Switched-capacitor circuits can be used in digital to analog converters (DAC), analog to digital converters (ADC), instrumentation amplifiers, voltage-to-frequency converters, data converters, programmable capacitor arrays, balanced modulators, peak detectors, oscillators, and so on.
Main components of the switched capacitor circuits generally include switches, capacitors, and so on. The switched capacitor circuits employed in various types of ADCs, such as delta sigma ADCs, usually use a large number of capacitors and switches to realize the circuit. Ideally, the capacitance of the capacitors needs to be in a desired ratio, but may deviate from the desired ratio due to reasons, such as imperfections in the manufacturing processes and change of operating conditions (e.g., temperature, voltage, etc.). Such deviations are generally referred to as capacitor mismatch. Due to capacitor mismatches, a delta sigma ADC may not generate an accurate output. This may necessitate minimizing the number of capacitors in the circuit. In addition, switches in switched capacitor circuits may introduce noise in the circuit, and reduce the signal-to-noise ratio of the signal.